Now that I've had he DEF deleted and the DPF thought I would post my MPG. I'm getting about 18Mpg average, around 600 miles per tank. They say it's a 36 gallon tank but every time I Fill it it the most it takes is 33 gallons, and that's with the fuel light being on for around 30 miles. Has anyone else done the same mods and have what there getting for mpg???